CODEWITHSUNDEEP
pythonvariablesglobal
In-young Choung
In-young Choung

Reputation: 809

Python Variable - name '' is not defined

Hello I am a newbie to Python.

Declaration of variables is frustrating as it should be easy but I have such hard time to make this work.. I've read other stackoverflow questions and apparently there is no such thing as initialization in Python and I need keyword: global before variable to use it in different places..

 @app.route('/calculate', methods = ['GET'])      

 def calculate(): 
      # get value from html by request.args.get()

Option1.

   global newWeightForSecondItem
   if weightT1 != weightT2:
       newWeightForSecondItem = convert(weightT1, weightT2, weight2)

Option 2.

   if weightT1 != weightT2:
       global newWeightForSecondItem = convert(weightT1, weightT2, weight2)

Neither works.. When I do such calculation below, I get an error: NameError: name 'newWeightForSecondItem' is not defined.

   if discountT2 == "percentage":
       finalPrice2 = float((float(price2) - (float(price2) * float(discount2))) / newWeightForSecondItem)
   elif discountT2 == "dollar":
       finalPrice2 = float((float(price2) - float(discount2)) / newWeightForSecondItem)


def convert(weightT1, weightT2, weight2):
   # converting calculation here 

return weight2


 # main method
 if __name__ == '__main__':
     app.debug = True
     app.run()

Upvotes: 1

Views: 5109

Answers (2)

In-young Choung
In-young Choung

Reputation: 809

I spent a lot time to figure out why I got this error. NameError: name 'newWeightForSecondItem' is not defined.

However, that was not the main issue. I forgot to convert string to float datatype for newWeightForSecondItem. After I changed it to float(newWeightForSecondItem), it works. This was a very easy mistake and I think python's error was not very helpful.

Thank you for all the comments, everyone.

Upvotes: 1

Gabriel Falcones
Gabriel Falcones

Reputation: 23

if you want to have newWeightForSecondItem as a global variable perhaps you can try this:

 newWeightForSecondItem = None

 @app.route('/calculate', methods = ['GET'])      
 def calculate():
     global newWeightForSecondItem
     if weightT1 != weightT2:
         newWeightForSecondItem = convert(weightT1, weightT2, weight2)

You declare/initialize the global variable, and then you can use it inside the function

Upvotes: 0

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